Safety tool joint



Patented Aug. 7, 1934 SAFETY TOOL JOINT Charles P. Skinner, Ventura, CallL, assignor to Byron Jackson 00., Los

. poration of Delaware Angeles, Calif., acor- Application July 8, 1,30, No. 486,374

7 Claims. (Cl. 285-146)- My invention relates to a safety tool joint that isespeciallydesignedforuseinthedrillinglines or strings that are utilized by rotarywell drilling rigs and the principal objects of my invention are,

3 to generally improve upon and simplify the construction of the existing forms of safety tool joints, to provide a joint or coupling of the character referred to that may be easily and quickly broken or disconnected by a reverse rotary movement of the drill string in which the joint is located and further, to provide a safety joint that is relatively simple in construction, inexpensive of manufacture and which when properly manipulated will provide a strong and rugged joint or 1 coupling between sections of the drill string or between the drill string and the drill, fishing tool or other tool or appliance that is associated with said drill string.

Inthedrillingofdeepwellsthetoolcarriedby the lower end of the drill string some times becomes anchored or stuck in the formation at the bottom of'the well hole and vif such conditions involve a fishing job for the removal of the tool, it is desirable to break or disconnect the drilling string adjacent to the anchored tool.

My invention provides a safety joint that may be arranged in the drill string directly above or adjacent to the tool at the lower end of the string and thus said string may be broken or discongo nected' at the desired point and thereby eliminate the danger or possibility of breaking or disconnecting a joint in the drill tube at some point in said drill tube is reversely rotated for the purpose ;of bringing about the desired break or disconnection.

My improved safety joint is designed so that it may be released or disconnectedunder much less ;=tortional strains developed by reverse rotation of the drill string, than is required to break.

or unscrew the ordinary tool joint used in drilling strings.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will hereinafter be more fully described and claimed and illustrated in the accompanying drawing, in which:

,Fig. 1 is an elevational view-bf a safety tool so joint embodying the principles of my invention. Fig. 2 is a longitudinal section through the of the joint and taken on theline 2-2 1 Fig. is a horlsontal section taken on the line Fig. 4 is an elevational view of the upper portion of a modified form of the joint.

Fig. 5 is a horizontal section similar to Fig. 3 and showing a modified form of the connection between the friction ring and the upper member so of the joint;

Referring by numerals to the accompanying drawing which illustrates a practical embodiment of my invention, 10 designates a cylindrical memher that forms the main body portion of the upas per member of the joint and formed integral with and projecting upwardly from the upper end of said body 10 is an externally threaded pin 11, whereby the joint may be readily connected to the internally threaded lower end'of a drill string member.

Formed integral with and depending from the body 10 is an axially disposed'cylindrical stem 12, the diameter of which is less than the diameter of body 10 and the external face of the lower portion of this stem is provided with quick acting threads 13.

Extending axially through the bodylo, pin 11 and stem 12 is-a circulation duct 14.

The underface of the shoulder formed between the lower end of body 10 and the stem 12 is notched to form a series of teeth 15, each tooth being provided with one inclined and with one abrupt face or shoulder 16 that occupies a'plane parallel with the axis of the body '10 and the underface 1'7 of each tooth or the face-between the shoulders 16 is inclined and the angle of inclinathe intermediate or upper portion thereof when tion is reversely arranged relative to the angularity of the threads 13.

In the event that quick acting threads 13 are right hand threads, as illustrated in Fig. 2, then the underfaces 17 of the teeth 15 are inclined toward the left hand, as illustrated inli'ig. 1.

Formed in the periphery of the upper portion of stem 12, above the quick acting threads 13 is a circumferential groove 18 and loosely arranged on the upper portion of stem 12 is a ring or collar 19,'the external diameter of which is approximately equal to the diameter of body 10.

The inner ends of screws or pins 20 that are seated in ring or collar 19 project into the groove 18, thereby retaining the collar in position on stem 12 and permitting said collar to move circumferentially and for a slight distance longitudinally.

The upper face of ring 19 is provided with teeth 21 having shoulders 22 at their ends that oppose the shoulders 18 on teeth 15 and said teeth 21 having inclined upper faces 23-that engage dino rectly against the inclined underfaces 17 of said teeth 15.

A cylindrical member 24, the diameter of which is equal to the diameters of collar 19 and body 10, forms the lower member of the safety joint and the upper portion of this lower member is provided with an axial chamber 25 that is threaded for the reception of the quick acting threads 13 on stem 12.

. Formed in the lower portion of the body 24 is a threaded recess 26 that is adapted to receive a correspondingly threaded pin on a drill string member or tool and the upper end of this recess 26 communicates with chamber 25 by means of an axially arranged p ning 27.

A shoulder 28 is formed between the upper end of opening 27 and the lower end of opening 26' and seated on this shoulder is a packing ring or gasket 29 that is adapted to be engaged and compressed by the lower end of threaded stem 12 when the latter is screwed to its limit of movement into the threaded opening 25 in member 24. i H When my improved safety joint is located iii a drill string, pin 11 is screwed into the lower end of one of the members or sections of the string and threaded recess 26 receives the correspondingly threaded pin on the upper end of a tool shank or a drill string member just above the drill or tool that is carried by the string.

Threaded stem 12 is screwed into the threaded chamber 25 and whentightened therein, the inclined underfaces 17 on the underface ofbody 10 will engage the corresponding inclined faces 23 on the upper face of'collar 19 and force said collar downwardly with longitudinal pressure so as to cause the underface of said ring or collar to frictionaliy engage the upper face of the body 24.

Inasmuch as the engaging inclined faces 17 and 23 are oppositely inclined relative to the threads 13, the normal rotation of the drill string will tend to move the joint member 10, having the inclined faces 17 and the collar 19 having the in clined faces 23, in opposite directions with the result thatthe joint friction between threadedstem 12 and joint member 24 will be practically eliminated and the friction will be transferred to the joint between the upper face of member 24' and the underi'ace of ring or collar 19.

This Joint friction between body member 24 and ring 19 will prevail as long as the drill string is rotated in the direction so as to cause the inclined underfaces 17 of teeth 15 to bear on the correspondingly teeth 21. I

When it becomes necessary to break or disconnect the safety joint the drill string is reversely rotated and following such action the inclined underfaces 17 -of teeth 15 will leave the inclined upper faces 23 of teeth 21, thereby instantly eliminating the joint friction between the upper end of body 24 and the underface of ring 19 and the threaded stem 12 will now unscrew from the threaded chamber 25 in joint member 24, thus bringing about the break or disconnection at the desired point, rather than at a joint in the intermediate or upper portion of the drill string.

When stem 12 is screwed into the threaded chamber 25 in member 24, packing ring 29 will be compressed so as to provide a fluid pressure tight joint between the lower end of stem 12 and the lower joint member 24.

In Fig. 4 I have shown a construction wherein the ring 19 is reversely arranged with the cooperating friction facesbetween theupper end of the ring and a corresponding shoulder on member inclined upper faces 23 of 10 and with the cooperating inclined faces formed on the lower end of said ring and on the upper end of the internally threaded member 24.

In Fig. 5 I have illustrated a modified arrangement for mounting the collar 19 on the upper portion of stem 12 and such construction involves the formation of a groove 30 in the inner face of ring 19, which groove registers with groove 18 on stem 12 and arranged in the ring channel, formed by p these registering grooves, is a plurality of balls 31 that are inserted into said channel through an opening 32 that is formed in collar 19 and which opening is normally closed by a removable plug 33.

-While I have shown the stem 12 as being provided with quick acting right hand threads, it will be understood that the pitch of these threads may be reversed and where such construction is employed, the inclination of the faces 17 and 23 will be reversed from the positions illustrated in Fig. 1.

It is obvious that the threaded pin 11 may depend from the lower end of member 24 and that the threaded recess 26 may be formed in the upper end of body member 10.

Thus it will be seen thatI have provided a safety releasing joint for deep well drilling strings and which joint is especially advantageous in permitting the drilling line or string to be easily and quickly disconnected at a point adjacent to, or immediately above the drill or other tool that is carried by the lower end of the drilling string and which joint is relatively simple in construction, inexpensive of manufacture, strong, rugged and durable and very eflective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various'parts of my improved safety tool joint may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. A safety joint, including a member having an inclined surface, a second member, a screwthreaded connection between the members, a ring mounted on one of the members for partial rotation and having an inclined surface adapted to bear against the inclined surface of the firstnamed member and an end to bear against the second member to limit threading together .of

the connection, the said inclined surfaces being pitched in the opposite direction to the threads of said connection and stop shoulders on said inclined surfaces for limiting rotation of the ring relative to the first-named member.

2. A safety joint, including a member having an inclined surface, a second member, a screwthreaded connection between the members, a ring mounted on one of the members for partial rotation and having an inclined surface adapted to bear against the inclined surface ofthe firstnamed member and an end to bear against the second member to limit threading together of the connection, the said inclined surfaces being pitched in the opposite direction to the threads of said connection and a ball in registering grooves in the ring and one of the members for holding the ring against displacement.

3. -A safety joint comprising an upper member nally threaded portion of the first mentioned on which bears against the inclined surface of the ring, the said inclined surfaces being pitched opposite to the threads of the said connection.

' 4. A safety joint comprising an upper member,

a lower member, a screw threaded connection between the members, a ring rotatable on one of said members, said ring bearing against the top of the lower member, the ring having an inclined surface on its upper end, said upper member having an inclined surface thereon which bears against the inclined surface of the ring, the said inclined surfaces being pitched opposite to the threads of the said connection, and means to hold said ring on the first named member against longitudinal displacement.

5. In a safety joint, two separable members, one having an internal screw thread and the other having an external screw thread adapted to be engaged in the thread of the first mentioned member, and a collar loosely arranged between said members and adapted to frictionally engage one of said members, the other of said members 4 and the collar having cooperating inclined faces pitched opposite to the said screw threads.

6. In a safety tool joint, a member having an externally threaded portion, an internally threaded member adapted to receive the extermember, a ring loosely arranged between the two members, one end of said ring having a substantially flat friction face that cooperates with a corresponding friction face on one of said members, and the other end of said ring being pro- .vided with an inclined face that cooperates with a. corresponding inclined face on the other memher, and the slope of said inclined faces being oppositely inclined to the slope of said threads.

'7. In a safety tool joint, an internally threaded member, the member having an externally threaded portion that is adapted to be screwed into said internally threaded member, a ring loosely mounted between said members, one end of said ring and one of said members having relatively smooth friction faces, and the other end of said ring and the other one of said members being provided with a plurality of cooperating inclined faces, the slope of said inclined faces being oppositely inclined to the slope of said threads, and packing means between the ends CHARLES P. SKINNER. 

